Re: `automake` error

[Patrice Dumas]

On Sat, Feb 12, 2022 at 06:30:36PM +0000, Werner LEMBERG wrote:
> 
> automake: error: cannot open < doc/tp_api/tp_api.texi: No such file or 
> directory

I indeed added recently the doc/tp_api/tp_api.texi for distribution as
it is useful for the HTML customization API and referenced in many
places in the HTML customization API manual.

It is not a hand written manual, but it is generated based on the POD
sections of perl modules.  In addition to being generated, it is
possible that the perl module (Pod::Simple::PullParser) needed to
generate it is not present.  Presence/absence of this module corresponds
to the --enable-perl-api-texi-build configure option, and the automake
conditional BUILD_PERL_API_TEXI.  Also, be aware that this manual
actually depends, implicitely, on included files, like
api_includes/Texinfo-*.texi generated at the same time as the
doc/tp_api/tp_api.texi file.

Note that Pod::Simple::PullParser should normally be present, as it is a
core perl module.  I do not know since when.

I think that there are two issues
1. how to bootstrap automake when the file is not present, but the file
  (and the api_includes/Texinfo-*.texi files) can be generated.
2. what to do to make sure that things goes smoothly if the file cannot
  be generated

For 1, one possibility would be to generate a fake tp_api.texi from
autogen.sh suitable for automake with a timestamp in the past similar
with what Gavin proposed.

For 2., I have no good idea.  Maybe we could simply require
Pod::Simple::PullParser and make it a non optional dependency of
Texinfo (like Data::Dumper, l 64 of configure.ac) to make this issue
disappear.

One way to avoid part of these issues would be to have
doc/tp_api/tp_api.texi and all the files in
doc/tp_api/api_includes/*.texi are under version control.  We already do
that in similar cases, for instance autogenerated man pages.  It does
not solve all the issues, but could help in some cases.

-- 
Pat